Fluidizing chamber



Nov. 4, 1969 w, K. FACER ETAL FLUIDIZING CHAMBER Filed March 25, 1964 &.H mm x 6% k A H mm m E :8 N3 m IIN- give. 25% uaifim EMF x Q Q S Q mIll/1 I I'II I IHHIHHHHHHHHHHHH OOOOQOOOOOOOOOOOOOO OOOOOOOOOOOOOINVENTORS WALTER k. FACE/i and Y I Af/orney United States Patent3,476,081 FLUIDKZING CHAMBER Walter K. Facer, Parma, and Jane H. M.Rigo, Cleveland, Ohio, assignors to United States Steel Corporation, acorporation of Delaware Filed Mar. 25, 1964, Ser. No. 354,594 lint. Cl.Bc 3/04, 3/132; F163 /40 US. Cl. 118-620 13 Claims ABSTRACT OF THEDISCLOSURE A fluidized bed coating apparatus adapted to treat asubstrate of indefinite length passing horizontally therethrough.Vertically arranged compartmentizing walls in the fluidizing chamber.The chamber being sealed by pressurized air-sealing means, through whichthe substrate passes and which are secured at either the chamber endwalls or at a compartmentizing wall whereby to select an effectivelength of fluidizing chamber. Fluid mediumdeflecting plates disposed insaid chamber and mounted in close proximity to, but above, the sealedopenings of the chamber.

This invention relates to an apparatus for coating an elongated body andmore particularly to the coating of a steel wire with resin. This typeof coating has been applied by various methods and apparatuses. ChurchPatent No. 3,108,022 dated Oct. 22, 1963, shows one type of apparatuswhich has been used. However, we have found that this apparatus, likeothers of which we have knowledge, has various disadvantages. In Churchthe air used at the seals is not uniformly distributed and will havelittle fluidizing effect. Also the chamber containing the fluidized bedmust be relatively air tight so that there is a problem in charging theresin. We have also discovered when using a fluidized bed of a fixedlength that it is diflicult to obtain suitable coatings on wires ofdifferent sizes and to vary the thickness of the coating, Difficulty isalso encountered in obtaining a suitable primer on the wire beforecoating.

It is therefore an object of our invention to provide an apparatus forcoating an elongated object with resin wherein different size objectscan be provided with suitable coatings of various thicknesses.

A further object is to provide such apparatus which need not have anenclosed or air tight top.

A still further object is to provide such apparatus which efficientlyutilizes the gas supplied to the fluidized bed.

These and other objects will be more apparent after referring to thefollowing specification and attached drawings, in which:

FIGURE 1 is a schematic view of the coating line of our invention;

FIGURE 2 is a view, partly in section, of the priming unit of ourinvention;

FIGURE 3 is a view, partly in section, of the coating unit of ourinvention; and

FIGURE 4 is a sectional view of a detail of the coating unit.

Referring more particularly to the drawings, reference numeral 2indicates a pay off reel for supporting a coil of wire W to be coated.The wire W passes through standard roll straighteners 3 to a cleaningtank 4 of any suitable type and then through a water rinse tank 6. Fromhere the wire W passes successively through a priming unit 8, dryingunit 10, preheat induction coil 12, coating chamber 14, post heatinduction coil 16, fusion area 18 and water quench 20 to a take up 22where it is coiled. While the description will be directed to thecoating of wire; strand, cord, rope, strip or like elongated structuresmay be coated as well with only slight modification.

3,476,081 Patented Nov. 4, 1969 ice The priming unit 8, as shown inFIGURE 2 includes a chamber 24 having a spiraled cord wipe 26 thereinthrough which the wire W passes. A liquid primer is delivered intochamber 24 and directed onto wire W through a conduit 28 and is returnedto a reservoir (not shown) through a drain 30. The coating chamber 14 asshown in FIGURES 3 and 4 has end walls 32 and 34 with aligned openings36 and 38 therein. An entry air seal 40 is supported on the wall 32 andan exit air seal 42 is supported on the wall 34. The seal 40 includes ahollow cylindrical member 44 having an externally threaded reduceddiameter portion 46 and a larger diameter portion 48. The portion 46 hasan axial opening 50 therethrough which is only slightly larger than thediameter of the wire W. The portion 48 has an opening or chamber 52therein which is connected to the opening 50 by means of a beveledportion 54which is preferably arranged at an angle of 60 to the-axisofthe wire. Threads 56 are provided on the inlet side of opening 52 and anozzle 58 is threaded into the threads 56. The forward end of nozzle 58is tapered at the same angle as tapered portion 54. The air seal 40 isattached to the wall 32 by means of a nut 60 threaded on portion 46. Agasket or other sealing member 62 is provided between the portion 48 andthe outside of wall 32. The nozzle 58 is threaded into threads 56 anamount such that a conical port 64 is provided for air passage. The sizeof the opening of port 64 may be varied as desired- A lock nut 66threaded on the outside of nozzle 58 and bearing against member 44 holdsthe nozzle in adjusted position. Air is delivered into the chamber 52through a conduit 68. The air seal 42 has essentially the sameconstruction as air seal 40 and corresponding parts are indicated bypriming the reference numerals applied to the parts of air seal 40. Theopenings through portion 46' and nozzle 58' are substantially largerthan the openings through portion 46 and nozzle 58. Air is deliveredinto chamber 52' at diametrically opposed positions through conduits 70and 72.

An air diffusion board 74 is arranged a short distance above bottom 76of the chamber 14. A manifold 78 supported on top of chamber 14 has achamber 80 around its periphery. Inner walls 82 of the manifold 78 haveclosely spaced holes 84 therein for a purpose which will appear later. Aconduit 86 is connected to the manifold 78 and leads to a suction fan88. A deflector plate 90 is mounted on each end wall above the air sealand extends downwardly and inwardly. Preferably the plates terminate ashort distance from each side of chamber 14. Two vertical partitions 92are arranged in the chamber 14 intermediate the ends thereof. Eachpartition 92 includes flanged members 94 around the transverse peripheryof chamber 14. The bottom of each flanged member 94 preferably has adownwardly extending flange 95 which divides board 74 into sections. Aplate 96 is attached to the member 94 with a sealing member 98therebetween. Each plate 96 has an opening 100 therethrough which is inalignment with openings 36 and 38. Dividers 102 are provided in plenumchamber 104 formed between the bottom 76 and diffusion board 74. A seal103 is provided between the top flange of divider 102 and the bottom ofboards 74.

Air is delivered into the chamber 104 from an air source (not shown)through air manifold 106 and branch conduits 108, 110 and 112. Theconduits 108, 110 and 112 have valves 114, 116 and 118 therein. Aremovable cover 120 is preferably provided over at least a portion ofthe top of the manifold 78. Air is delivered along the wire W into theinduction coil 12 through an air conduit 122. Valves 124, 126, 128 and130 control the flow of air through conduits 68, 70 and 72 into the airseals and through the conduit 122.

In operation, wire W is threaded through the line and a granulated resinmaterial 132 is placed in the coating chamber 14. This resin may bethermoplastic or thermosetting. The type of resin does not form any partof the present invention but the following resins have been used:Cellulosic, chlorinated polyether, eposy, nylon, polyester,polyethylene, dry blended vinyl and pre-fused freeze-ground vinyl.Assuming that the wire is of small diameter that a thick coating is tobe applied, the exit seal 42 will be attached to the end wall 34 asshown. The line is then started in operation with the valves 114, 116and 118 being open. As the straightened clean wire passes into chamber24 liquid primer is directed directly onto the wire W and after partialdraining the primer is more uniformly distributed by passage through thewool felt cord 26. At a given speed, primer feed, and wire diameter, thethickness of the primer may be varied by changing the number of wraps ofthe cord 26 around the wire. The primer materials form no part of thepresent invention but that sold by Michigan Chrome and Chemical Companyas MC1445 primer and that sold by Polymer Processes Incorporated as VCprimer have been used. The primer is then dried in the drying unit andthe wire W preheated as it passes through induction coil 12. Flow of airthrough conduit 122 into the coil 12 has been found necessary in orderto purge the priming fumes and to keep the coil free of accumulations.Most of the fumes will be driven back into drying chamber 10 by thisaid. As the wire W passes through the fluidized bed of powdered resin132 it picks up a coating of the same. The bed is kept in a fluidizedstate by means of the air passing through the diffusion board 74 andalso by the air passing through the air seals. The deflectors 90 preventthis latter air from rising directly through the bed at each end. Airmovement at the end seals prevents dead space in or around the seal soas to prevent agglomeration of the resin at the wire entrance and exitpoints. The air at the exit seal blows excess powder from the wire andprevents escape of powder from the tank. The wire from the coatingchamber 14 passes through the fusion zone 18 where the particles ofresin on the wire fuse together and to the wire to obtain a smoothsurface. In some instances heat will be supplied to the wire W by meansof the induction coil 16. This is done only when additional heat isrequired on the wire which is most likely to occur with small diameterwires. The fused wire then passes through the water quench 20 and henceto the take-up 22 where it is coiled.

When coating wires of larger diameter it has been found that the lengthof the fluidized bed should be reduced. This is also true when a thinresin coating is desired or when the wire is passed through the line atslow speeds. When this is done the exit seal 42 and deflector 90 areattached to one of the partitions 92 and the powdered resin is placedonly in the space between the seals. Assuming that the seal 42 anddeflector 90 are placed on the first of the partitions 92, as shown inbroken lines in FIGURE 3, valves 116 and 118 are closed and valve 114opened. Also the openings 84 between the first partition 92 and the endwall 34 are closed in any suitable manner. This may be done by merelyplacing adhesive tape thereover. The flange 9S, divider 102 and seal 103restrict air flow from chamber 104 to the fluidized bed in the firstcompartment of chamber 14. Fumes and air passing through the openings 84are drawn through conduit 86 by means of suction fan 88.

We claim:

1. Apparatus for coating a moving elongated object comprising means formoving said object longitudinally, a chamber for containing a powderedresin; means for delivering gas to the bottom of said chamber includingexit means in an upper portion thereof for the egress of the fluidizinggas; an opening formed at each end wall of the chamber, horizontallyaligned with one another; chamber seal means disposed at each saidopening; each seal means comprising an apertured nose portion removablysecured at the opening of the associated chamber end wall, said noseportion being formed on an end wall of an enlarged cylindrical chamberwhich extends outwardly of said fluidizing chamber, the other end wallof said cylindrical chamber including a screw-threaded opening which isin alignment with the aperture through said nose portion, an externallyscrew-threaded elongated nozzle member extending into said cylindricalchamber and engaged with the screw-threads at the opening in said otherend wall whereby said nozzle is axially adjustable for translation toand from the apertured nose portion, the aperture exending through saidnozzle being at least as large as and in horizontal alignment with theaperture in said nose portion, said nozzle being of a length whereby theforward end portion thereof is closely spaced from the end of said noseportion which forms a part of the associated cylindrical chamber endwall, pressurized gas feed means communicating with said cylindricalchamber, the aperture of said nose portion being chamfered at theassociated end wall, the said nozzle end portion being beveled tocomplement said chamfered part so as to form a forwardly directedannular slit whereby pressurized gas feed into the cylindrical chamberwall pass through said annular slit in direction toward said fluidizingchamber; the apertures through said nose portions being of a size toclosely accommodate the passage of said elongated object therethrough;and a downwardly and inwardly directed deflector plate mounted on eachfluidizing chamber end wall, in the proximity of but above the openingtherein, whereby to intercept fluidizing medium thereat and inside ofsaid fluidizing chamber.

2. Apparatus according to claim 1 wherein said exit means includes aplurality of openings disposed about the periphery of a top portion ofthe fluidizing chamber and means for applying suction at said openings.

3. Apparatus according to claim 2 combined with means to preheat saidarticle, said means comprising an induction coil through which theelongated object passes and disposed in the proximity of the entranceseal to the fluidizing chamber; and

means delivering a scavenging gas to said induction coil whereby toinhibit any accumulation thereon.

4. Apparatus according to claim 3 wherein the apertures of the exit sealnose and nozzle parts are slightly larger than the correspondingentrance seal parts whereby to closely accommodate the coated object.

5. Apparatus according to claim 4 wherein said fluidizing chamber iscompartmented by at least one vertically extending, apertured wallmember;

the aperture in said vertical wall member being in horizontal alignmentwith the apertures of said seal means; said seal means being removablysecurable at said aperture of said vertical wall member whereby aneffective length of fluidizing chamber may be selected;

said means for delivering fluidizing gas include means for selectivelydelivering such fluidizing gas to each compartment; and

said vertical wall member including a deflector plate which correspondsto the deflector plates at the fluidizing chamber end walls.

6. Apparatus according to claim 1 wherein said fluidizing chamber iscompartmented by at least one vertically extending, apertured wallmember;

the aperture in said vertical wall member being in horizontal alignmentwith the apertures of said seal means; said seal means being removablysecurable at said aperture of said vertical wall member whereby aneffective length of fluidizing chamber may be selected;

said means for delivering fluidizing gas include means for selectivelydelivering such fluidizing gas to each compartment; and

said vertical wall member including a deflector plate which correspondsto the deflector plates at the fluidizing chamber end walls.

7. Apparatus according to claim 6 wherein the fluidizing chamber iscompartmented by a plurality of the said vertical wall member.

-8. Apparatus according to claim 6 wherein the apertures of the exitseal nose and nozzle parts are slightly larger than the correspondingentrance seal parts whereby to closely accommodate the coated objects.

9. Apparatus according to claim 8 wherein said exit means includes aplurality of openings disposed about the periphery of a top portion ofthe fluidizing chamber and means for applying suction at said openings.

10. Apparatus according to claim 7 combined with means to preheat saidarticle, said means comprising an induction coil through which theelongated object passes and disposed in the proximity of the entranceseal to the fluidizing chamber, and

means delivering a scavenging gas to said induction coil whereby toinhibit any accumulation thereon.

11. Apparatus according to claim 10 combined with means to apply aprimer to said object;

means to dry the primer-coated object prior to passage of said objectthrough the means to preheat; and

said means to move being adapted to continuously move the elongatedobject, seriatim through each of the object treating means.

12. Apparatus for coating a moving elongated object comprising means formoving said object longitudinally; a chamber for containing a powderedresin; means for delivering gas to the bottom of said chamber whereby tofiuidize said powdered resin; said chamber including exit means in anupper portion thereof for the egress of the fluidizing gas; an openingformed at each end wall of the chamber, generally horizontally alignedwith one another; chamber seal means disposed at each said opening; eachseal means having an aperture therethrough of a size to closelyaccommodate the passage of said elongated object therethrough and meansfor feeding pressurized gas into said aperture in a direction towardsaid fluidizing chamber; and a downwardly and inwardly directeddefiector plate mounted on each fluidizing chamber end wall, in theproximity of but above the opening therein, whereby to interceptfluidizing medium thereat and inside of said fluidizing chamber.

13. Apparatus according to claim 12 in which said fluidizing chamber iscompartmented by at least one ver tically extending, apertured wallmember; the aperture in said vertical wall member being in horizontalalignment with the apertures of said seal means; seal means on saidapertured wall member; said seal means being removably securable wherebyan effective length of fluidizing chamber may be selected; said meansfor delivering fluidizing gas include means for selectively deliveringsuch fluidizing gas to each compartment; and said vertical wall memberincluding a deflector plate which corresponds to the deflector plates atthe fluidizing chamber end walls.

References Cited UNITED STATES PATENTS 1,595,486 8/1926 Minton.

2,540,006 1/1951 Otto 118-405 X 2,602,959 7/1952 Fenlin 118-405 X2,750,681 6/1956 Berry.

3,004,861 10/1961 Davis 118-309 X 3,108,022 10/1963 Church 118-404 X3,199,491 8/1965 Bader 118-405 X 3,208,868 9/1965 Strobel et a1. 117-21X 3,208,869 9/1965 Starr et a1 118-405 X 3,233,582 2/1966 Sharetts etal. 118-404 3,270,364 9/ 1966 Steele 15306 MORRIS KAPLAN, PrimaryExaminer US. Cl. X.R.

